Tunneling magnetoresistive element and method of manufacturing the same

ABSTRACT

Insulating layers are formed on both sides of a multilayer film, and bias layers are formed in contact with at least portions of both end surfaces of a free magnetic layer. The bias layers are formed so as not to extend to the upper surface of the multilayer film. In this construction, a sensing current from electrode layers appropriately flows through the multilayer film, and a bias magnetic field can be supplied to the free magnetic layer from the bias layers through both side surfaces of the free magnetic layer. Furthermore, the magnetic domain structure of the free magnetic layer can be stabilized to permit an attempt to decrease instability of the reproduced waveform and Barkhausen noise.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a tunneling magnetoresistiveelement mounted on a magnetic reproducing apparatus, for example, a harddisk device, or the like, or another magnetic sensing device.Particularly, the present invention relates to a tunnelingmagnetoresistive element which can stably produce a rate of change inresistance, and which can be formed with high reproducibility, and amethod of manufacturing the same.

[0003] 2. Description of the Related Art

[0004]FIG. 21 is a partial sectional view illustrating the structure ofa conventional tunneling magnetoresistive element.

[0005] In FIG. 21, reference numeral 1 denotes an electrode layer madeof, for example, Cu, W, Cr or the like.

[0006] An antiferromagnetic layer 2, a pinned magnetic layer 3, aninsulating barrier layer 4 and a free magnetic layer 5 are laminated inturn to form a multilayer film 6 on the electrode layer 1.

[0007] The antiferromagnetic layer 2 is made of an existingantiferromagnetic material such as a NiMn alloy film or the like, andheat treatment of the antiferromagnetic layer 2 produces an exchangecoupling magnetic field between the pinned magnetic layer 3 made of aferromagnetic material such as a NiFe alloy film or the like and theantiferromagnetic layer 2 to pin the magnetization direction of thepinned magnetic layer 3 in the Y direction (height direction) shown inFIG. 21.

[0008] The insulating barrier layer 4 is made of an existing insulatingmaterial such as Al₂O₃ or the like, and the free magnetic layer is madeof the same material as the pinned magnetic layer 3, such as a NiFealloy film or the like.

[0009] Referring to FIG. 21, bias layers 9 made of a hard magneticmaterial such as a Co—Pt alloy film or the like are formed on both sidesof the multilayer film 6 in the track width direction (the X directionshown in the drawing).

[0010] The bias layers 9 supply a bias magnetic field to the freemagnetic layer 5 in the X direction shown in the drawing to orient themagnetization direction of the free magnetic layer 5 in the X direction.

[0011] As shown in FIG. 21, an electrode layer 10 is formed on themultilayer film 6 and the bias layers 9.

[0012] The tunneling magnetoresistive element serves as a reproducingmagnetic element utilizing a tunneling effect for detecting a leakagemagnetic field from a recording medium. When a sensing current issupplied to the multilayer film 6 from the electrode layers 1 and 10 inthe Z direction shown in the drawing, a tunneling current changes basedon the magnetization relation between the free magnetic layer 5 and thepinned magnetic layer 3 to cause a change in resistance, therebydetecting a recording signal by the change in resistance.

[0013] However, the structure of the tunneling magnetoresistive elementshown in FIG. 21 has the following problem.

[0014] Since the sensing current supplied from the electrode layers 1and 10 flows not only through the multilayer film 6 but also through thebias layers 9 formed on both sides of the multilayer film 6 to fail toobtain a TMR effect, thereby significantly deteriorating the functionand properties of the reproducing magnetic element.

[0015]FIG. 22 shows another tunneling magnetoresistive element having astructure which is improved for resolving the above problem.

[0016] Referring to FIG. 22, insulating layers 7 made of, for example,Al₂O₃ or the like, are formed on both sides of the multilayer film 6 inthe track width direction (the X direction shown in the drawing).

[0017] By forming the insulating layers 7, a plane surface extends onthe same plane as the upper surface of the multilayer film 6, the biaslayers 9 made of a hard magnetic material such as a Co—Pt film beingrespectively formed on the insulating layers 7 with underlying layers 8of Cr provided therebetween.

[0018] Each of the hard magnetic bias layers 9 is formed to furtherextend from the insulating layer 7 to the upper surface of themultilayer film 6 by a width dimension T1. As a result, themagnetization direction of the free magnetic layer is oriented in the Xdirection by a bias magnetic field from the bias layers 9.

[0019] In the structure shown in FIG. 22, the insulating layers 7 areformed on both sides of the multilayer film 6, and thus the sensingcurrent from the electrode layers 1 and 10 appropriately flows throughthe multilayer film 6 with less shunt current. Also, in this structure,the bias magnetic field from the bias layers 9 flows into the freemagnetic layer 5 from the top thereof, not from the sides of the freemagnetic layer 5.

[0020] However, the tunneling magnetoresistive element shown in FIG. 22has the following problem.

[0021] As shown in FIG. 22, a bias magnetic field A from the bias layers9 is oriented in the track width direction (the X direction shown in thedrawing) to supply a magnetic field to the free magnetic layer 5 in theX direction. However, at the same time, a magnetic field B oriented inthe direction opposite to the bias magnetic field A occurs in theportion of the free magnetic layer 5 which contacts of the extension ofeach of the bias layers 9 on the multilayer film 6. The occurrence ofthe magnetic field B destabilizes the magnetic domain structure of thefree magnetic layer 5 to cause the occurrence of Barkhousen noise ordestabilize a reproduced waveform, thereby deteriorating reproducingcharacteristics.

[0022] As described below, the structure of the magnetic element shownin FIG. 22 causes difficulties in forming the bias layers 9 with highalignment accuracy, causing variations in the width dimension T1 of theextension of each of the bias layers 9. Particularly, the bias layers 9are formed to extend on a sensitive zone of the multilayer film 6, whichsubstantially exhibits a magnetoresistive effect, and thus the magneticdomain structure of the sensitive zone is significantly destabilized dueto the occurrence of the magnetic field B. Also, the extensions of thebias layers 9 to the sensitive region significantly decrease a zonewhich can exhibit the magnetoresistive effect, thereby deterioratingcharacteristics.

[0023] The occurrence of the magnetic field B is due to the formation ofthe underlying layers 8 made of Cr between the free magnetic layer 5 andthe bias layers 9. The presence of the underlying layers 8 interruptsmagnetic coupling between the free magnetic layer 5 and the bias layers9.

[0024] There is thus the idea that the underlying layers 8 are removedto directly joint the free magnetic layer 5 and the bias layers 9.However, without the underlying layers 8, the coercive force of the biaslayers 9 cannot be ensured to cause difficulties in controlling crystalorientation, thereby significantly deteriorating hard magneticproperties.

[0025] The method of manufacturing the tunneling magnetoresistiveelement shown in FIG. 22 also has the following problems.

[0026] As shown in FIG. 23, after the electrode layer 1, the multilayerfilm 6 and the insulating layers 7 are formed, the bias layer 9 isformed on the multilayer film 6 and the insulating layers 7.

[0027] In FIG. 24, a resist layer 11 is formed on the bias layer 9, andthen exposed and developed to form an aperture pattern 11 a having apredetermined with dimension in the central portion of the resist layer11. Then, the bias layer 9 exposed from the aperture pattern 11 a isremoved by etching to form the bias layers 9 having the shape shown inFIG. 9.

[0028] However, it is difficult to form the aperture pattern 11 a withhigh precision at a predetermined portion of the resist layer 11 at thetop of the multilayer film 6, which has a very small width dimension,thereby causing variations in the shape of the bias layers 9 todeteriorate reproducibility.

[0029] Furthermore, in the step of etching the bias layers 9 exposedfrom the aperture pattern 11 a, a portion of the free magnetic layer 5below the bias layer 9 is also possibly removed to make it difficult tocontrol the etching time or the like. Since the free magnetic layer 5 isformed to a small thickness of several tens nm, a variation occurs inthe properties even when only a small amount of the free magnetic layer5 is removed.

[0030] Also, the structure of the tunneling magnetoresistive elementshown in FIG. 22 easily produces a variation in a reproducing gap. Asshown in FIG. 22, the length from the lower electrode layer 1 to theupper electrode layer 10 is h1 in the central portion where the biaslayers 9 are not formed on the multilayer film 6, while the length is h2in the portion where the bias layers 9 are formed on the multilayer film6, the length h2 being longer than the length h1. Therefore, a variationoccurs in the thickness of the reproducing gap within the widthdimension of the multilayer film 6 in the track width direction (the Xdirection shown in the drawing), easily causing an adverse effect on thereproducing characteristics.

SUMMARY OF THE INVENTION

[0031] The present invention has been achieved for solving the aboveproblems of a conventional element, and an object of the presentinvention is to provide a tunneling magnetoresistive element permittingappropriate supply of a bias magnetic field to a free magnetic layer tostabilize a reproduced waveform, and a method of manufacturing thetunneling magnetoresistive element exhibiting high reproducibility offormation.

[0032] In an aspect of the present invention, there is provided atunneling magnetoresistive element comprising a multilayer filmcomprising an antiferromagnetic layer, a pinned magnetic layer formed incontact with the antiferromagnetic layer so that the magnetizationdirection is pinned by an exchange coupling magnetic field with theantiferromagnetic layer, and a free magnetic layer formed on the pinedmagnetic layer with an insulating barrier layer provided therebetween,electrode layers formed above and below the multilayer film, insulatinglayers formed on both sides of the multilayer film in the track widthdirection, and domain control layers respectively formed on theinsulating layers so as to contact at least portions of both sidesurfaces of the free magnetic layer, for orienting the magnetizationdirection of the free magnetic layer in a direction crossing themagnetization direction of the pinned magnetic layer, wherein the domaincontrol layers are formed so as not to extend to the upper surface ofthe multilayer film.

[0033] In the present invention, the antiferromagnetic layer, the pinnedmagnetic layer, the insulating barrier layer and the free magnetic layerare formed in turn from the bottom to form the multilayer film, and theinsulating layers and the domain control layers are formed on both sidesof the multilayer film.

[0034] The domain control layers are formed in contact with at leastportions of both sides surfaces of the free magnetic layer so as not toextend to the upper surface of the multilayer film.

[0035] By providing the insulating layers on both sides of themultilayer film, as described above, a sensing current from theelectrode layers appropriately flows through the multilayer film todecrease a shunt loss of the sensing current, thereby improvingreproduced output.

[0036] Since the domain control layers are formed in contact with bothside surfaces of the free magnetic layer, a bias magnetic field from thedomain control layers is appropriately supplied to the free magneticlayer through the sides thereof, permitting magnetization control of thefree magnetic layer.

[0037] Furthermore, unlike in the conventional example shown in FIG. 22,the domain control layers are formed so as not to extend to the uppersurface of the multilayer film, and thus the reverse magnetization fieldB does not occur in the free magnetic layer, thereby stabilizing themagnetic domain structure of the free magnetic layer. More specifically,the free magnetic layer can be appropriately put into a single magneticdomain structure state.

[0038] In another aspect of the present invention, there is provided atunneling magnetoresistive element comprising a multilayer filmcomprising an antiferromagnetic layer, a pinned magnetic layer formed incontact with the antiferromagnetic layer so that the magnetizationdirection is pinned by an exchange coupling magnetic field with theantiferromagnetic layer, a free magnetic layer formed on the pinedmagnetic layer with an insulating barrier layer provided therebetween,electrode layers formed above and below the multilayer film, insulatinglayers formed on both sides of the multilayer film in the track widthdirection, and domain control layers formed on the insulating layers soas to contact at least portions of both side surfaces of the freemagnetic layer, for orienting the magnetization direction of the freemagnetic layer in a direction crossing the magnetization direction ofthe pinned magnetic layer, wherein the multilayer film comprises acentral sensitive zone having excellent reproducing sensitivity so thata magnetoresistive effect can be substantially exhibited, and dead zonesformed on both sides of the sensitive zone and having low reproducingsensitivity so that the magnetoresistive effect cannot be substantiallyexhibited, and the domain control layers are formed so as to extend onthe multilayer film.

[0039] In the present invention, the domain control layers are formed toextend on the multilayer film, but extend only on the dead zones of themultilayer film.

[0040] In the multilayer film, not the entire region exhibits themagnetoresistive effect, but only the central area has excellentreproducing sensitivity and can substantially exhibit themagnetoresistive effect. The area having excellent reproducingsensitivity is referred to as a “sensitive zone”, and the areas on bothsides of the sensitive zone, which have poor reproducing sensitivity,are referred to as “dead zones”. The sensitive zone and the dead zonesin the multilayer film are measured by, for example, a micro-trackprofile method.

[0041] In the present invention, the domain control layers may be formedto extend on the dead zones. Even when as in a conventional element,underlying layers are interposed between the domain control layers andthe multilayer film, for controlling the crystal orientation of thedomain control layers, a reverse magnetic field (refer to referencecharacter B shown in FIG. 22) occurring in the free magnetic layer isproduced only in the dead zones thereof, thereby causing no adverseeffect on the reproducing characteristics.

[0042] Furthermore, the domain control layers are formed on the deadzones, not formed on the sensitive zone, and thus the reproducing gapwithin the sensitive zone has a uniform thickness, causing no fear ofdeterioration in characteristics.

[0043] In a still another aspect of the present invention, there isprovided a tunneling magnetoresistive element comprising a multilayerfilm comprising a free magnetic layer, a pinned magnetic layer formed onthe free magnetic layer with an insulating barrier layer providedtherebetween, and an antiferromagnetic layer formed on the pinnedmagnetic layer, for pinning the magnetization direction of the pinnedmagnetic layer by an exchange coupling magnetic field, electrode layersformed above and below the multilayer film, domain control layers formedon both sides of the multilayer film in the track width direction so asto contact at least portions of both side surfaces of the free magneticlayer, for orienting the magnetization direction of the free magneticlayer in a direction crossing the magnetization direction of the pinnedmagnetic layer, and insulating layers respectively formed on the domaincontrol layers, wherein the insulating layers are formed so as not toextend to the upper surface of the multilayer film.

[0044] In the present invention, the free magnetic layer, the insulatingbarrier layer, the pinned magnetic layer and the antiferromagnetic layerare laminated in turn from the bottom to form the multilayer film.

[0045] Since the domain control layers are formed to contact at leastportions of both side surfaces of the free magnetic layer, a biasmagnetic field can be appropriately supplied to the free magnetic layerfrom the domain control layers.

[0046] Also, the insulating layers are formed on the domain controllayers, and thus a sensing current from the electrode layersappropriately flows through the multilayer film to decrease a shunt lossof the sensing current, thereby permitting an attempt to improvereproduced output.

[0047] Since the insulating layers are formed so as not to extend to theupper surface of the multilayer film, no variation occurs in thethickness of the reproducing gap within the width dimension of themultilayer film in the track width direction, thereby causing no fear ofdeteriorating characteristics.

[0048] In a further aspect of the present invention, there is provided atunneling magnetoresistive element comprising a multilayer filmcomprising a free magnetic layer, a pinned magnetic layer formed on thefree magnetic layer with an insulating barrier layer providedtherebetween, and an antiferromagnetic layer formed on the pinnedmagnetic layer, for pinning the magnetization direction of the pinnedmagnetic layer by an exchange coupling magnetic field, electrode layersformed above and below the multilayer film, domain control layers formedon both sides of the multilayer film in the track width direction so asto contact at least portions of both side surfaces of the free magneticlayer, for orienting the magnetization direction of the free magneticlayer in a direction crossing the magnetization direction of the pinnedmagnetic layer, and insulating layers formed on the domain controllayers, wherein the multilayer film comprises a central sensitive zonehaving excellent reproducing sensitivity so that the magnetoresistiveeffect can be substantially exhibited, and dead zones formed on bothsides of the sensitive zone and having poor reproducing sensitivity sothat the magnetoresistive effect cannot be substantially exhibited, andthe insulating layers are formed so as to extend on the dead zones ofthe multilayer film.

[0049] In the present invention, the insulating layers are formed toextend on the dead zones of the multilayer film, not on the sensitivezone thereof, and thus no variation occurs in the thickness of thereproducing gap within the sensitive zone, causing no fear ofdeteriorating characteristics.

[0050] In the present invention, underlying layers are preferably formedbelow the domain control layer, for controlling the crystal orientationof the domain control layers. This can sufficiently maintain themagnetic properties of the domain control layer.

[0051] In the present invention, with the domain control layers formedto extend on the dead zones of the multilayer film, a magnetic filed inthe direction opposite to the bias magnetic field of the domain controllayers occurs in the multilayer film due to the presence of theunderlying layers. However, the reverse magnetic field occurs within thedead zones, and thus the reproducing characteristics are not adverselyaffected.

[0052] Each of the domain control layers preferably comprises a hardmagnetic material.

[0053] In the present invention, each of the domain control layers maycomprise a laminated film of a ferromagnetic layer and a secondantiferromagnetic layer, the ferromagnetic layers being in contact withat least portions of both side surfaces of the free magnetic layer.

[0054] In the present invention, the insulating layers may comprise anantiferromagnetic insulating layer exhibiting an antiferromagneticproperty, and the domain control layers may comprise a ferromagneticlayer.

[0055] In this case, the second antiferromagnetic layer or theantiferromagnetic layer is preferably made of α-Fe₂O₃.

[0056] A method of manufacturing a tunneling magnetoresistive element ofthe present invention comprises:

[0057] (a) the step of forming an electrode layer on a substrate, andthen laminating an antiferromagnetic layer, a pinned magnetic layer inwhich magnetization is pinned in a predetermined direction by anexchange coupling magnetic field with the antiferromagnetic layer, aninsulating barrier layer and a free magnetic layer in turn from thebottom to form a multilayer film;

[0058] (b) the step of forming, on the multilayer film, a lift-offresist layer having notched portions formed on the lower side thereof;

[0059] (c) the step of removing both sides of the mulitlayer filmleaving at least a portion of the multilayer film below the resistlayer;

[0060] (d) the step of forming insulating layers on both sides of themultilayer film so that the multilayer film-side ends of the uppersurfaces of the insulating layers are lower than both ends of the uppersurface of the free magnetic layer;

[0061] (e) the step of forming domain control layers on the insulatinglayers by sputtering obliquely to the substrate so that the domaincontrol layers contact both ends of the free magnetic layer, and themultilayer film-side ends of the upper surfaces of the domain controllayers coincide with the both ends of the upper surface of themultilayer film; and

[0062] (f) the step of removing the resist layer, and forming anelectrode layer on the multilayer film and the domain control layers.

[0063] In the present invention, as described above, the lift-off resisthaving notched portions formed on the lower side thereof is used forforming the insulating layers and the domain control layers on bothsides of the multilayer film.

[0064] Therefore, unlike a conventional manufacturing method (refer toFIGS. 23 and 24), alignment precision for forming an aperture pattern ina resist layer is unnecessary, and thus less variation occurs in theshape of the domain control layers as compared with the conventionalmethod. Therefore, a tunneling magnetoresistive element can bemanufactured with high reproducibility.

[0065] In the above-described manufacturing method, the domain controllayers can be formed in contact with both side surfaces of the freemagnetic layer so as not to extend to the upper surface of themultilayer film.

[0066] A method of manufacturing a tunneling magnetoresistive element ofthe present invention comprises:

[0067] (g) the step of forming an electrode layer on a substrate, andthen laminating an antiferromagnetic layer, a pinned magnetic layer inwhich magnetization is pinned in a predetermined direction by anexchange coupling magnetic field with the antiferromagnetic layer, aninsulating barrier layer and a free magnetic layer in turn from thebottom to form a multilayer film;

[0068] (h) the step of forming, on a sensitive zone of the multilayerfilm, a lift-off resist layer having notched portions formed on thelower side thereof;

[0069] (i) the step of removing both sides of the mulitlayer filmleaving at least a portion of the multilayer film below the resistlayer;

[0070] (j) the step of forming insulating layers on both sides of themultilayer film so that the multilayer film-side ends of the uppersurfaces of the insulating layers are lower than both ends of the uppersurface of the free magnetic layer;

[0071] (k) the step of forming domain control layers on the insulatinglayers by sputtering obliquely to the substrate so that the domaincontrol layers contact both ends of the free magnetic layer, and extendon dead zones of the multilayer film; and

[0072] (l) the step of removing the resist layer, and forming anelectrode layer on the multilayer film and the domain control layers.

[0073] This manufacturing method is capable of manufacturing a tunnelingmagnetoresistive element with high reproducibility, and forming thedomain control layers to extend only on the dead zones of the multilayerfilm.

[0074] A method of manufacturing a tunneling magnetoresistive element ofthe present invention comprises:

[0075] (m) the step of forming an electrode layer on a substrate, andthen laminating a free magnetic layer, an insulating barrier layer, apinned magnetic layer, and an antiferromagnetic layer for pinningmagnetization of the pinned magnetic layer in a predetermined directionby an exchange coupling magnetic field in turn from the bottom to form amultilayer film;

[0076] (n) the step of forming, on the multilayer film, a lift-offresist layer having notched portions formed on the lower side thereof;

[0077] (o) the step of removing both sides of the multilayer filmleaving a portion of the multilayer film below the resist layer;

[0078] (p) the step of forming domain control layers on both sides ofthe multilayer film so that the multilayer film-side ends contact atleast portions of both ends of the free magnetic layer;

[0079] (q) the step of forming insulating layers on the domain controllayers by sputtering obliquely to the multilayer film so that themultilayer film-side ends of the upper surfaces of the insulating layerscoincide with both ends of the upper surface of the multilayer film; and

[0080] (r) the step of removing the resist layer, and forming anelectrode layer on the multilayer film and the insulating layers.

[0081] In this case, the free magnetic layer, the insulating barrierlayer, the pinned magnetic layer and the antiferromagnetic layer arelaminated in turn from the bottom to form the multilayer film. Inaddition, the domain control layers and the insulating layers are formedon both sides of the multilayer film by using the lift-off resist layerto cause less variation in the shapes of the domain control layers andthe insulating layers, thereby permitting the manufacture of a tunnelingmagnetoresistive element with high reproducibility.

[0082] In the present invention, the insulating layers may be formed soas not to extend to the upper surface the multilayer film.

[0083] A method of manufacturing a tunneling magnetoresistive element ofthe present invention comprises:

[0084] (s) the step of forming an electrode layer on a substrate, andthen laminating a free magnetic layer, an insulating barrier layer, apinned magnetic layer, and an antiferromagnetic layer for pinningmagnetization of the pinned magnetic layer in a predetermined directionby an exchange coupling magnetic field in turn from the bottom to form amultilayer film;

[0085] (t) the step of forming, on a sensitive zone of the multilayerfilm, a lift-off resist layer having notched portions formed on thelower side thereof;

[0086] (u) the step of removing both sides of the multilayer filmleaving at least a portion of the multilayer film below the resistlayer;

[0087] (v) the step of forming domain control layers on both sides ofthe multilayer film so that the multilayer film-side ends contact atleast portions of both ends of the free magnetic layer;

[0088] (w) the step of forming insulating layers on the domain controllayers by sputtering obliquely to the multilayer film so that theinsulating layers extend on dead zones of the multilayer film; and

[0089] (x) the step of removing the resist layer, and forming anelectrode layer on the multilayer film and the insulating layers.

[0090] In this case, a tunneling magnetoresistive element can bemanufactured with high reproducibility. Also, the insulating layers canbe formed to extend only on the dead zones of the multilayer film.

[0091] In the present invention, underlying layers are preferably formedbelow the domain control layers, for controlling crystal orientation ofthe domain control layers. The underlying layers can be formed in thesame step as the insulating layers and the domain control layers.

[0092] In the present invention, in the step (d), (j), (p) or (v), theinsulating layers or the domain control layers are preferably formed bysputtering vertically to the substrate.

[0093] In the present invention, each of the domain control layerspreferably comprises a hard magnetic material or a laminated film of aferromagnetic layer and a second antiferromagnetic layer, theferromagnetic layers being brought into contact with at least portionsof both side surfaces of the free magnetic layer.

[0094] In the present invention, each of the insulating layers maycomprise an antiferromagnetic insulating layer exhibitingantiferromagnetism, and each of the domain control layers may comprise aferromagnetic layer.

[0095] In the present invention, the second antiferromagnetic layer orthe antiferromagnetic insulating layer exhibiting antiferromagnetism maybe made of α-Fe₂O₃.

BRIEF DESCRIPTION OF THE DRAWINGS

[0096]FIG. 1 is a partial sectional view showing the structure of atunneling magnetoresistive element according to an embodiment of thepresent invention;

[0097]FIG. 2 is a partial sectional view showing the structure of atunneling magnetoresistive element according to another embodiment ofthe present invention;

[0098]FIG. 3 is a partial sectional view showing the structure of atunneling magnetoresistive element according to still another embodimentof the present invention;

[0099]FIG. 4 is a partial sectional view showing the structure of atunneling magnetoresistive element according to a further embodiment ofthe present invention;

[0100]FIG. 5 is a partial sectional view showing the structure of atunneling magnetoresistive element according to a still furtherembodiment of the present invention;

[0101]FIG. 6 is a partial sectional view showing the structure of atunneling magnetoresistive element according to a further embodiment ofthe present invention;

[0102]FIG. 7 is a partial sectional view showing the structure of atunneling magnetoresistive element according to a further embodiment ofthe present invention;

[0103]FIG. 8 is a partial sectional view showing the structure of atunneling magnetoresistive element according to a further embodiment ofthe present invention;

[0104]FIG. 9 is a drawing showing a step of a method of manufacturing atunneling magnetoresistive element according to the present invention;

[0105]FIG. 10 is a drawing showing a step after the step shown in FIG.9;

[0106]FIG. 11 is a drawing showing a step after the step shown in FIG.10;

[0107]FIG. 12 is a drawing showing a step after the step shown in FIG.11;

[0108]FIG. 13 is a drawing showing a step after the step shown in FIG.12;

[0109]FIG. 14 is a drawing showing a step substituted for the step shownin FIG. 12;

[0110]FIG. 15 is a drawing showing a step of a method of manufacturinganother tunneling magnetoresistive element according to the presentinvention;

[0111]FIG. 16 is a drawing showing a step after the step shown in FIG.15;

[0112]FIG. 17 is a drawing showing a step after the step shown in FIG.16;

[0113]FIG. 18 is a drawing showing a step after the step shown in FIG.17;

[0114]FIG. 19 is a drawing showing a step after the step shown in FIG.18;

[0115]FIG. 20 is a drawing showing a step substituted for the step shownin FIG. 18;

[0116]FIG. 21 is a partial schematic view showing the structure of aconventional tunneling magnetoresistive element;

[0117]FIG. 22 is a partial schematic view showing the structure ofanother conventional tunneling magnetoresistive element;

[0118]FIG. 23 is a drawing showing a step of a method of manufacturingthe tunneling magnetoresistive element shown in FIG. 22; and

[0119]FIG. 24 is a drawing showing a step after the step shown in FIG.23.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0120]FIG. 1 is a partial sectional view showing the structure of atunneling magnetoresistive element of the present invention.

[0121] In FIG. 1, reference numeral 20 denotes an electrode layer madeof, for example, W (tungsten), Cr (chromium), or the like.

[0122] A multilayer film 21 is formed on the electrode layer 20 to haveboth side surfaces 21 a which are inclined so that the width dimensionincreases in the downward direction of the drawing. In the presentinvention, the multilayer film 21 has the following construction.

[0123] As shown in FIG. 1, an antiferromagnetic layer 22 is formed onthe electrode layer 20. The antiferromagnetic layer 22 preferablycomprises a X—Mn alloy (wherein X is at least one element of Pt. Pd, Ir,Rh, Ru, and Os). Particularly, Pt is preferably selected as X to use aPtMn alloy for the antiferromagnetic layer 22.

[0124] In the present invention, the antiferromagnetic layer 22 maycomprise a X—Mn—X′ alloy (wherein X′ is ate least one element of Ne, Ar,Kr, Xe, Be, B, C, N, Mg, Al, Si, Pt, V, Cr, Fe, Co, Ni, Cu, Zn, Ga, Ge,Zr, Nb, Mo, Ag, Cd, Sn, Hf, Xa, W, Re, Au, Pd, and the rare earthelements).

[0125] The X—Mn or X—Mn—X′ alloy has excellent corrosion resistance, ahigh blocking temperature and a high exchange coupling magnetic field(exchange anisotropic magnetic field), as compared with a NiMn alloy andFeMn alloy used for conventional antiferromagnetic layers.

[0126] The antiferromagnetic layer 22 has a protrusion 22 a formed nearthe center thereof to protrude in the Z direction shown in the drawing.A pinned magnetic layer 26 comprising three layers is formed on theprotrusion 22 a.

[0127] The pinned magnetic layer 26 comprises ferromagnetic layers 23and 25, and a nonmagnetic layer 24 provided therebetween.

[0128] Each of the ferromagnetic layers 23 and 25 comprises, forexample, a NiFe alloy film, a Co film, a CoNiFe alloy film, a CoFe alloyfilm, or the like. The nonmagnetic layer 24 is composed of Ru, Rh, Ir,Cr, Re, Cu, or the like.

[0129] Although heat treatment produces an exchange coupling magneticfield between the pinned magnetic layer 26 and the antiferromagneticlayer 22, the magnetization directions of the ferromagnetic layers 22and 25 are made antiparallel to each other by the exchange couplingmagnetic field. For example, the ferromagnetic layer 23 is magnetized inthe Y direction shown in the drawing, and the ferromagnetic layer 25 ismagnetized in the direction opposite to the Y direction. This isreferred to as a “ferrimagnetic state”. This construction can stabilizethe magnetization state of the pinned magnetic layer 26, and increasethe exchange coupling magnetic field produced at the interface betweenthe pinned magnetic layer 26 and the antiferromagnetic layer 22.

[0130] An insulating barrier layer 27 is formed on the pinned magneticlayer 26. The insulating barrier layer 27 is preferably made of aninsulating material, for example, an oxide of at least one elementselected from Al, Mg, Nb, Ni, Gd, Ge, Si and Hf. Namely, the insulatingbarrier layer 27 is made of Al₂O₃, AlO_(x), GeO_(x), NiO, GdO_(x), MgO,or the like.

[0131] The insulating barrier layer 27 may be made of a paramagneticinsulating material comprising a perovskite-type oxide R_(1-x)A_(x)MnO₃(R is at least one element selected from trivalent rare earth ions suchas La³⁺, Pr³⁺, Nd³⁺, and the like, trivalent alkali earth ions such asCa²⁺, Sr²⁺, Ba²⁺, and the like). In this case, R and A are preferablyLa³⁺ and Sr²⁺, respectively, and the composition ratio x is preferably0.26 or less. Alternatively, R and A are preferably Pr³⁺ and Ca²⁺,respectively.

[0132] In the present invention, the insulating barrier layer 27preferably has a granular structure in which metal fine particles aredispersed in an insulating matrix.

[0133] Furthermore, a free magnetic layer 30 comprising two layers isformed on the insulating barrier layer 27. A layer 28, i.e., a layer 28formed in contact with the insulating barrier layer 27, preferablycomprises a Co film or a CoFe alloy film. A layer 29 comprises a NiFealloy film, a CoNiFe alloy film, a CoFe alloy film, or the like. It wasconfirmed that by providing a Co film or a CoFe alloy film in contactwith the insulating barrier layer 27, the rate of change in resistancecan be improved.

[0134] Next, insulating layers 31 are formed on the antiferromagneticlayer 22 to be located on both sides of the multilayer film 21 in thetrack width direction (the X direction shown in the drawing), and biaslayers (domain control layers) 33 are formed on the insulating layers31.

[0135] The insulating layers are preferably made of, for example, AlO,Al₂O₃, SiO₂, Xa₂O₅, XiO, AlN, AlSiN, SiN, SiN, Si₃N₄, NiO, WO, WO₃, BN,CrN, or SiON.

[0136] The bias layers 33 formed on the insulating layers 31 withunderlying layers 32 provided therebetween are formed for orienting themagnetization direction of the free magnetic layer 30 in the track widthdirection (the X direction shown in the drawing). In the tunnelingmagnetoresistive element shown in FIG. 1, each of the bias layers 33comprises a hard magnetic material, for example, a Co—Pt alloy film, aCo—Cr—Pt alloy film, or the like.

[0137] The underlying layers 32 respectively formed below the biaslayers 33 are provided for controlling crystal orientation of the biaslayers 33 to ensure coercive force. When each of the bias layers 33comprises a hard magnetic material as described above, each of theunderlying layers 32 comprises a Cr film, a bcc—Fe film, a Fe—Co alloyfilm, or the like.

[0138] Furthermore, as shown in FIG. 1, an electrode layer 34 made ofthe same material as the electrode layer 20 is formed on the multilayerfilm 21 and the bias layers 33.

[0139] In the structure of the tunneling magnetoresistive element shownin FIG. 1, the bias layers 33 are formed in contact with at leastportions of both side surfaces of the free magnetic layer 30 in thetrack width direction (the X direction). In this structure, a biasmagnetic field is supplied to the end surfaces of the free magneticlayer 30 from the bias layers 33 in the track width direction to orientthe magnetization direction of the free magnetic layer 30 in the Xdirection.

[0140] With the bias layers 33 each comprising a hard magnetic material,the insulating layers 31 may be partially inserted by about 10 nm orless in the interfaces between the side surfaces of the free magneticlayer 30 and the bias layers 33.

[0141] In order to form the bias layers 33 in contact with portions ofboth side surfaces of the free magnetic layer 30, the insulating layers31 must be formed below the bias layers 33 so that the multilayerfilm-side ends 31 a of the upper surfaces of the insulating layers 31are lower than the ends 30 a of the upper surface of the free magneticlayer 30. This structure can easily be formed with high reproducibilityby the manufacturing method which will be described below.

[0142] In the embodiment shown in FIG. 1, the multilayer film-side ends33 a of the upper surfaces of the bias layers 33 coincide with both ends21 b of the upper surface of the multilayer film 21, and the bias layers33 are formed so as not to extend to the upper surface of the multilayerfilm 21.

[0143] In comparison with the conventional example shown in FIG. 22, thebias layers 9 shown in FIG. 22 are formed to extend to the upper surfaceof the multilayer film 6 as described above, and thus the magnetic fieldB in the direction opposite to the bias magnetic field A occurs in thefree magnetic layer 5 in contact with the extended portion of each ofthe bias layers 9, thereby causing a factor of destabilization of themagnetic domain structure of the free magnetic layer 5.

[0144] On the other hand, in the present invention, the bias layers areformed not to extend to the upper surface of the multilayer film 21.Therefore, the above-described magnetic field reverse to the biasmagnetic field does not occur in the free magnetic layer 30. Thus, inthe present invention, the domain structure of the free magnetic layer30 can be stabilized to easily put the magnetization of the freemagnetic layer into a single magnetic domain state.

[0145] Also, the case shown in FIG. 22 has a problem in which theextensions of the bias layers 9 to the upper surface of the multilayerfilm 6 cause a difference in the reproducing gap length between theportion where each of the bias layers is extended, and the portion wherethe bias layers are not extended, within the width dimension of themultilayer film 6 in the track width direction. While in the presentinvention, the bias layers 33 are formed not to extend to the uppersurface of the multilayer film 6, and thus the reproducing gap length isuniform within the width dimension of the multilayer film 6 in the trackwidth direction, thereby maintaining good reproducing characteristics.

[0146] In the tunneling magnetoresistive element shown in FIG. 1, asensing current from the electrode layers 20 and 24 flows through themultilayer film 21 in the Z direction shown in the drawing. Themagnitude of the tunneling current passing through the multilayer film21 depends upon the relation between the magnetization directions of thepinned magnetic layer 26 and the free magnetic layer 30.

[0147] When an external magnetic field enters the tunnelingmagnetoresistive element in the Y direction, magnetization of the freemagnetic layer 30 is changed by the influence of the external magneticfield. This causes a change in the magnitude of the tunneling current sothat the change in amount of the current is detected as a change inelectric resistance. Therefore, the change in electric resistance can bedetected as a change in voltage to detect the external magnetic fieldfrom a recording medium.

[0148] In the present invention, the insulating layers 31 are formed onboth sides of the multilayer film 21 in the track width direction (the Xdirection), and thus less shunt current occurs in the sensing currentfrom the electrode layers 20 and 34. Therefore, the sensing currentappropriately flows through the multilayer film 21 in the Z direction,permitting an attempt to improve the reproduced output of the element.

[0149] As described above, the bias layers 33 are formed on both sidesof the free magnetic layer 30 in the track width direction, and thus abias magnetic field can be supplied to the free magnetic layer 30through the side surfaces to appropriately orient the magnetizationdirection of the free magnetic layer 30 in the track width direction.

[0150] Furthermore, the bias layers 33 are formed not to extend to theupper surface of the multilayer film 21, and thus the domain structureof the free magnetic layer can be stabilized, thereby permitting anattempt to decrease instability of a reproduced waveform and Barkhausennoise. Also, the reproducing gap can be uniformly formed within thewidth dimension of the multilayer film 21 in the track width direction.

[0151]FIG. 2 is a partial sectional view showing the structure of atunneling magnetoresistive element according to another embodiment ofthe present invention.

[0152] This tunneling magnetoresistive element shown in FIG. 2 isdifferent from that shown in FIG. 1 only in the structure of the biaslayers 33, and the structures and materials of other layers are the sameas FIG. 1.

[0153] Namely, in the structure shown in FIG. 2, the multilayer film 21comprises the antiferromagnetic layer 22, the pinned magnetic layer 26,the insulating barrier layer 27 and the free magnetic layer 30, whichare laminated in turn from the bottom, and the insulating layers 31, theunderlying layers 32 and the bias layers 33 are formed on both sides ofthe multilayer film 32 in the track width direction (the X direction).

[0154] The bias layers 33 are formed in contact with at least portionsof both side surfaces of the free magnetic layer 30 in the track widthdirection (the X direction). In this structure, a bias magnetic field issupplied to the free magnetic layer 30 from the bias layers 33 throughthe side surfaces of the free magnetic layer 30 in the X direction,thereby orienting the magnetization direction of the free magnetic layer30 in the X direction.

[0155] As shown in FIG. 2, the bias layers 33 are formed to extend tothe upper surface of the multilayer film 21, but the bias layers 33 areformed only on the dead zones of the multilayer film 21, not formed onthe sensitive zone thereof.

[0156] The dead zones and the sensitive zone are measured by amicro-track profile method.

[0157] In the micro-track profile method, a signal recorded on amicrotrack is scanned with the tunneling magnetoresistive element in thetrack width direction. The area where an output of 50% or more of themaximum reproduced output is obtained is defined as the sensitive zone,and the areas on both sides of the sensitive zone are defined as thedead zones where output is 50% or less of the maximum output. In thedead zones, the reproducing function is ineffective, and only the DCresistance (DCR) is simply increased.

[0158] On the other hand, in the sensitive zone, the reproducingfunction is effective, and the magnetoresistive effect is substantiallyexhibited. Therefore, the width dimension of the sensitive zone in thetrack width direction substantially corresponds to a track width Tw (ora magnetic track width M-Tw). By the way, the minimum width dimensionbetween the bias layers 33 on the upper surface of the multilayer film21 is referred to as an “optical track width O-Tw”, and the track widthTw generally means the optical track width.

[0159] In the present invention, the bias layers 33 may be formed toextend on the dead zones. The extension of the bias layers 33 produces amagnetic field in the dead zones in the direction opposite to the biasmagnetic field of the bias layers 33.

[0160] However, in each of the dead zones, a longitudinal bias magneticfield is actually strongly applied in the forward direction to make thearea insensitive, and thus the domain structure is unlikely to be madeunstable even when the reverse magnetic field is applied from theextension of each of the bias layers.

[0161] Furthermore, even if the dead zones lose the reproducing functionto destabilize the domain structures thereof, no problem occurs in thereproducing function as long as the domain structure of the sensitivezone is stabilized. In addition, each of the dead zones has a small areahaving a width dimension of about 30 nm at the most. Therefore, evenwhen a local reverse magnetic field is applied to the small areas, thewide sensitive zone having a large width dimension is less affected bythe reverse magnetic field. Therefore, the tunneling magnetoresistiveelement of the present invention has an appropriate reproducingfunction.

[0162] In the present invention, the ratio of the width dimension T2 ofthe extension of each of the bias layers 33 on the multilayer film 21 tothe width dimension of the upper surface of the multilayer film 21 is0%<(width dimension T2/width dimension of upper surface of themultilayer film 21)≦10%. This can avoid the bias layers 33 from beingformed to extend on the sensitive zone, thereby maintaining appropriatereproducing characteristics.

[0163] Specifically, the width dimension T2 is preferably 0 nm<T2≦30 nm.This can avoid the bias layers 33 from being formed to extend on thesensitive zone, thereby maintaining appropriate reproducingcharacteristics.

[0164] In the structure shown in FIG. 2, the bias layers 33 are formednot to extend on the sensitive zone of the multilayer film 21, and thusthe reproducing gap length within the width dimension of the sensitivezone in the track width direction is uniform, thereby maintainingappropriate reproducing characteristics.

[0165]FIG. 3 is a partial sectional view showing the structure of atunneling magnetoresistive element according to still another embodimentof the present invention.

[0166] As shown in FIG. 3, a multilayer film 35 is formed on anelectrode layer 20. The order of lamination of layers which constitutethe multilayer film 35 is opposite to the multilayer film 21 shown inFIGS. 1 and 2.

[0167] Namely, a free magnetic layer 30, an insulating barrier layer 27,a pinned magnetic layer 26 and an antiferromagnetic layer 22 arelaminated in that order from the bottom. A material of each of thelayers is the same as described above with reference to FIG. 1.

[0168] Also, bias layers 33 are formed on both sides of the multilayerfilm 35 in the track width direction (the X direction shown in thedrawing) on the electrode layer 20 with underlying layers 32 providedtherebetween and each comprising a Cr film or the like. The underlyinglayers 32 control crystal orientation of the bias layers 33 to securecoercive force of the bias layers 33. Therefore, the hard magneticproperties of the bias layers 33 are sufficiently maintained.

[0169] The bias layers 33 are formed in contact with at least portionsof both side surfaces of the free magnetic layer 30. Therefore, a biasmagnetic field is supplied to the free magnetic layer 30 from the biaslayers 33 through the end surfaces of the free magnetic layer 30 in thetrack width direction (the X direction shown in the drawing) to orientthe magnetization direction of the free magnetic layer 30 in the Xdirection.

[0170] As shown in FIG. 3, insulating layers 31 are formed on the biaslayers 33 with nonmagnetic intermediate layers 36 provided therebetweenand made of Ta or the like. The nonmagnetic intermediate layers 36 arenot necessarily formed.

[0171] As shown in FIG. 3, the insulating layers 31 are formed not toextend to the upper surface of the multilayer film 35, and themultilayer film-side ends 31 a of the upper surfaces of the insulatinglayers 31 coincide with both ends 35 b of the multilayer film 35.

[0172] Therefore, the length of the reproducing gap is uniform within inthe width dimension of the multilayer film in the track width direction,thereby sufficiently maintaining the reproducing characteristics.

[0173] In this embodiment, the insulating layers 31 are formed on bothsides of the multilayer film 35 in the track width direction, and thus asensing current from the electrode layers 20 and 34 appropriately flowsthrough the multilayer film 35 with less shunt current, therebysufficiently maintaining the reproducing characteristics.

[0174] In the structure shown in FIG. 3, the bias layers 33 can beformed in contact with both end surfaces of the free magnetic layer 30,and thus the magnetic domain structure of the free magnetic layer 30 canbe stabilized to decrease instability of the reproduced waveform andBarkhausen noise.

[0175]FIG. 4 is a partial sectional view showing the structure of atunneling magnetoresistive element according to a further embodiment ofthe present invention.

[0176] The structure shown in FIG. 4 is different from that shown inFIG. 3 only in the structure of insulating layers 31, and the structuresand materials of other layers are the same as those shown in FIG. 1.

[0177] As shown in FIG. 4, the insulating layers 31 are formed to extendon the dead zones of the multilayer film 35.

[0178] The ratio of the width dimension T2 of the extension of each ofthe insulating layers 31 to the width dimension of the upper surface ofthe multilayer film 35 in the track width direction (the X directionshown in the drawing) is preferably 0%<(width dimension T2/widthdimension of the upper surface of the multilayer film)≦10%.Specifically, the width dimension T2 is preferably 0 nm<T2≦30 nm. Thispermits the formation of the insulating layers 31 only on the dead zonesof the multilayer film 35, and avoid the insulating layers 31 from beingformed to extend on the sensitive zone.

[0179] The sensitive zone and the dead zones are measured by themicro-track profile method described above with reference to FIG. 2. Inthe present invention, even when the insulating layers 31 are formed toextend to the upper surface of the multilayer film 35, the insulatinglayers 31 extend only on the dead zones, and thus the reproducing gaphas a uniform length within the width dimension of the sensitive zone inthe track width direction, causing no adverse effect on the reproducingcharacteristics.

[0180] Each of the tunneling magnetoresistive elements shown in FIGS. 5to 8 comprises means for supplying a bias magnetic field to a freemagnetic layer, which is different from the tunneling magnetoresistiveelements shown in FIGS. 1 to 4 in.

[0181] Like in the structures shown in FIGS. 1 and 2, in the structuresshown in FIGS. 5 and 6, a multilayer film 21 formed on an electrodelayer 20 comprises an antiferromagnetic layer 22, a pinned magneticlayer 26, an insulating barrier layer 27 and a free magnetic layer 30,which are laminated in turn from the bottom. Furthermore, insulatinglayers 31 are formed on the antiferromagnetic layer 22 to be located onboth sides of the multilayer film 21 in the track width direction (the Xdirection). A ferromagnetic layer 41 is formed on each of the insulatinglayers 31 through an underlying layer 40. As shown in FIG. 5, theferromagnetic layers 41 are formed in contact with at least portions ofboth end surfaces of the free magnetic layer 30 in the track widthdirection.

[0182] A second antiferromagnetic layer 42 is formed on each of theferromagnetic layers 41. In this embodiment, magnetization of each ofthe ferromagnetic layers 41 is pinned in the X direction by an exchangecoupling magnetic field produced between the ferromagnetic layer 41 andthe second antiferromagnetic layer 42, and a bias magnetic field issupplied to the end surfaces of the free magnetic layer 30 from theferromagnetic layers 41 in the X direction to orient magnetization ofthe free magnetic layer 30 in the X direction.

[0183] The ferromagnetic layers 41 comprise the same material as thepinned magnetic layer 26 and the free magnetic layer 30, and the secondantiferromagnetic layers 42 comprise the same material as theantiferromagnetic layer 22.

[0184] In FIG. 5, the ferromagnetic layers 41 and the secondantiferromagnetic layers 42 are formed so as not to extend to the uppersurface of the multilayer film 21. This can appropriately decreaseinstability of the reproduced waveform and Barkhausen noise withoutcausing destabilization of the magnetic domain structure of the freemagnetic layer 30.

[0185] The underlying layers 40 respectively provided below theferromagnetic layers 41 are not necessarily formed. However, when theunderlying layers 40 are used, the underlying layers 40 preferablycomprises a film of Ta, Hf, Ti, Zr, or the like. The crystal orientationof the ferromagnetic layers 41 can be controlled by the underlying layer40 to secure the predetermined exchange bias magnetic field. In thiscase, the free magnetic layer 30 and the ferromagnetic layers 41 aredirectly joined together by exchange interaction, and thus thedepositing angle of the underlying layers 40 is preferably controlled toprevent interposition of the underlying layers 40 at the junctioninterfaces between the free magnetic layer 30 and the ferromagneticlayers 41.

[0186] In FIG. 5, the ferromagnetic layers 41 and the secondantiferromagnetic layers 42 may be formed to extend on the dead zones ofthe multilayer film 21. Also, the second antiferromagnetic layers 42 maybe formed below the ferromagnetic layers 41. Namely, the thickness ofthe insulating layers 31 is slightly decreased so that the secondantiferromagnetic layers 42 and the ferromagnetic layers 41 arelaminated on the insulating layers 31. In this case, the ratio of theconductive layers (the second antiferromagnetic layers 42 and theferromagnetic layers 41) in direct contact with both sides of themultilayer film 21 is increased. Therefore, in order to decrease a shuntcurrent of the sensing current into these layers, the secondantiferromagnetic layers 42 are preferably made of an antiferromagneticinsulating material having antiferromagnetism, which will be describedbelow.

[0187] In FIG. 6, antiferromagnetic layers 43 having antiferromagnetismare deposited on the antiferromagnetic layer 22 to be located on bothsides of the multilayer film 21 in the track width direction (the Xdirection shown in the drawing), and ferromagnetic layers 44 aredeposited on the antiferromagnetic layer 43.

[0188] The ferromagnetic layers 44 are formed in contact with at leastportions of both end surfaces of the free magnetic layer 30 in the trackwidth direction. Consequently, a bias magnetic field is supplied to theside surfaces of the free magnetic layer 30 from the ferromagneticlayers 44 to orient magnetization of the free magnetic layer 30 in the Xdirection.

[0189] As described above, the antiferromagnetic insulating layers 43have antiferromagnetism. As the material of the antiferromagneticinsulating layers 43, a film of α-Fe₂O₃, NiO, NiCoO, or the like can beused. With the antiferromagnetic insulating layers 43 comprising aα-Fe₂O₃ film, exchange coupling magnetic fields are produced between theinsulating layers 43 and the ferromagnetic layers 44 to appropriatelypin magnetization of the ferromagnetic layers 44 in the X direction.

[0190] Furthermore, the antiferromagnetic insulating layers 43 have aninsulating property, and thus exhibit the same function as theinsulating layers 32 shown in FIGS. 1 to 5, thereby causing no shuntcurrent of the sensing current from the electrode layers 20 and 34 tothe antiferromagnetic insulating layers 43.

[0191] In comparison with the embodiment shown in FIG. 5, the embodimentshown in FIG. 5 has the need to laminate the four layers including theinsulating layer 31, the underlying layer 40, the ferromagnetic layer 41and the second antiferromagnetic layer 42 on either side of themultilayer film 21, while the embodiment shown in FIG. 6 requires theformation of only two layers including the antiferromagnetic insulatinglayer 43 and the ferromagnetic layer 44, thereby decreasing thethickness of the laminated film formed on either side of the multilayerfilm as well as the number of the manufacturing steps.

[0192] In the embodiment shown in FIG. 6, the ferromagnetic layers 44are formed to extend on the dead zones of the multilayer film 21, butthe ferromagnetic layers 44 may be formed so as not to extend on themultilayer film 21.

[0193] In FIG. 7, a multilayer film 35 formed on an electrode layer 20comprises a free magnetic layer 30, an insulating barrier layer 27, apinned magnetic layer 26 and an antiferromagnetic layer 22, which arelaminated in turn from the bottom.

[0194] Furthermore, underlying layers 40 each comprising a Ta film orthe like are formed on the electrode layer 20 so as to be located onboth sides of the multilayer film 35, and ferromagnetic layers 41 areformed on the underlying layers 40. The ferromagnetic layers 41 areformed in contact with at least portions of both end surfaces of thefree magnetic layer 30 in the track width direction.

[0195] Second antiferromagnetic layers 42 are formed on theferromagnetic layers 41, and insulating layers 31 are formed on theantiferromagnetic layers 42 through nonmagnetic intermediate layers 36each comprising a Ta film or the like. Like in the embodiment shown inFIG. 5, exchange coupling magnetic fields are produced between theferromagnetic layers 41 and the second antiferromagnetic layers 42 topin magnetization of the ferromagnetic layers 41 in the X direction, anda bias magnetic field is applied to the end surfaces of the freemagnetic layer 30 from the ferromagnetic layers 41 in the X direction toorient magnetization of the free magnetic layer 30 in the X directionshown in the drawing.

[0196] In the embodiment shown in FIG. 7, the insulating layers 31 areformed to extend on the dead zones of the mutlilayer film 35, but theinsulating layers 31 may be formed so as not to extend on the multilayerfilm 35.

[0197] In the embodiment shown in FIG. 8, underlying layer 40 composedof Ta or the like are formed on an electrode layer 20 to be located onboth sides of the mulilayer film 35, and ferromagnetic layers 44 areformed on the underlying layers 40. The ferromagnetic layers 44 areformed in contact with at least portions of both end surfaces of thefree magnetic layer 30 in the track width direction (the X directionshown in the drawing). Furthermore, antiferromagnetic insulating layers43 having antiferromagnetism are formed on the ferromagnetic layers 44.Each of the antiferromagnetic insulating layers 43 comprises a film ofα-Fe₂O₃, NiO, or the like.

[0198] Exchange coupling magnetic fields are produced between theferromagnetic layers 44 and the antiferromagnetic layers 43 havingantiferromagnetism to pin the magnetization of the ferromagnetic layers44 in the X direction, and a bias magnetic field is supplied to the sideend surfaces of the free magnetic layer 30 from the ferromagnetic layers44 in the X direction to orient the magnetization of the free magneticlayer 30 in the X direction.

[0199] In this embodiment, the antiferromagnetic insulating layers 43have the functions of both the insulating layers 31 and the secondferromagnetic layers 42 shown in FIG. 7, and thus the number of thelayers can be decreased to decrease the thickness of the laminated filmformed on either side of the multilayer film 35.

[0200] In the embodiment shown in FIG. 8, the antiferromagneticinsulating layers 43 are formed so as not to extend to the upper surfaceof the multilayer film 35, but the antiferromagnetic insulating layers43 may be formed to extend on the dead zones of the multilayer film 35.

[0201] Each of the above-described tunneling magnetoresistive elementsof the present invention can be used as a reproducing head which isprovided in a hard disk device, as well as a memory device of MRAM orthe like.

[0202] A reproducing head using any one of the above tunnelingmagnetoresistive elements may be a sliding type or a floating type, anda conventional type in which the element is exposed at the ABS, or atype such as a Yoke type, a Flux guide type, or the like, in which theelement is recessed from the ABS.

[0203] In each of the embodiments shown in FIGS. 1 to 8, the pinnedmagnetic layer 26 comprises the three layers, and the free magneticlayer 30 comprises the two layers. However, like in a conventionalelement, these layers may comprise a single layer, or the free magneticlayer 30 may be formed in a ferrimagnetic state.

[0204] The method of manufacturing a tunneling magnetoresistive elementof the present invention will be described below with reference to thedrawings. The drawings of FIGS. 9 to 13 show a first example of themanufacturing method of the present invention.

[0205] In the step shown in FIG. 9, an electrode layer 20, anantiferromagnetic layer 22, a pinned magnetic layer 26, an insulatingbarrier layer 27 and a free magnetic layer 30 are laminated on asubstrate 46. The layers ranging from the antiferromagnetic layer 22 tothe free magnetic layer 30 constitute a multilayer film 21. Also, aprotecting layer of Ta may be provided on the free magnetic layer 30.

[0206] The free magnetic layer 26 comprises three films in aferrimagnetic state. For example, each of ferromagnetic layers 23 and 25comprises a Co film, and a nonmagnetic layer 24 comprises a Ru film.Furthermore, the free magnetic layer 30 comprises two films. Forexample, a layer 28 comprises a Co film, and a layer 29 comprises a NiFealloy film.

[0207] The materials of the electrode layer 20, the antiferromagneticlayer 22 and the insulating barrier layer 27 are the same as those shownin FIG. 1.

[0208] As shown in FIG. 9, a lift-off resist layer 45 having notchedportions 45 a formed on the lower side thereof is formed on the freemagnetic layer 30. In this step, the width dimension of the lowersurface 45 b of the resist layer 45 in the track width direction (the Xdirection shown in the drawing) is set to a value which is the same asor longer than the width dimension of the sensitive zone of themultilayer film 21. The sensitive zone and the dead zones are measuredby the micro-track profile method to determine the width dimension ofthe sensitive zone in the track width direction (the X direction) beforethe step of forming the resist layer 45.

[0209] In the step shown in FIG. 10, both sides of the multilayer film21 in the track width direction (the X direction) are removed by dryetching by ion milling or the like to leave at least the portion of themultilayer film 21 which is covered with the resist layer 45.

[0210] In this step, as shown in FIG. 10, the antiferromagneticinsulating layer 22 is etched out to an intermediate position to form aprotrusion 22 a of the antiferromagnetic layer 22, which protrudes nearthe center thereof. The multilayer film 21 is etched as described aboveto form inclined end surfaces 21 a at both sides thereof in the trackwidth direction so that the width dimension gradually increases towardthe antiferromagnetic layer 22.

[0211] In the step shown in FIG. 11, the insulating layers 31 are formedon the antiferromagnetic layer 22 to be located on both sides of themultilayer film 21 in the track width direction. The insulating layers31 are deposited by sputtering in the R and S directions shown in thedrawing in a sputtering apparatus using a target opposite to thesubstrate 46 near parallel thereto. The sputtering apparatus preferablyuses a means of ion beam sputtering, long stroke sputtering, collimationsputtering, or the like, in which sputtered particles have highlinearity.

[0212] The R direction and S direction are preferably vertical orapproximately vertical to the substrate 46. In this case, the insulatinglayers 31 are not formed on the portions of both end surfaces of themultilayer film 21, which are shaded by the resist layer 45 when themultilayer film 21 is viewed from above.

[0213] Namely, the forming position and the thickness of the insulatinglayers 31 formed on both side surfaces of the multilayer film 21 can bechanged by appropriately controlling the maximum width dimension T3 ofthe resist layer 45 in the track width direction and the sputtering timefor the target.

[0214] In the present invention, bias layers 33 formed on the insulatinglayers 31 must be formed in contact with at least portions of both endsurfaces of the free magnetic layer 30 in the track width direction.

[0215] In order to achieve the above construction, the insulating layers31 must be deposited so that the multilayer film-side ends 31 a of theupper surfaces of the insulating layers 31 are lower than the ends 30 aof the upper surface of the free magnetic layer 30.

[0216] Therefore, the maximum width dimension T3 of the resist layer 45in the track width direction may be set to a value which is the same asor slightly shorter than the width dimension of the lower surface (i.e.,the lower surface of the layer 28 shown in FIG. 11) of the free magneticlayer 30, or the maximum width dimension T3 may be set to be longer thanthe width dimension of the free magnetic layer 30 so that at least thefree magnetic layer 30 is not completely seen when the multilayer film21 is viewed from above (a portion of the free magnetic layer 30 may beseen).

[0217] The resist layer 45 having the maximum width dimension T3appropriately controlled as described above is formed on the freemagnetic layer 30, and the insulating layers 31 are formed on both endsurfaces of the multilayer film 21 in the track width direction. In thiscase, both end surfaces of the multilayer film 21 are not completelycovered with the free magnetic layer 30 to create a state in which atleast portions of both end surfaces of the free magnetic layer 30 areexposed after the formation of the insulating layer 31.

[0218] In this step, an insulating material layer 31 b of the samematerial as the insulating layer 31 is formed on the resist layer 45.

[0219] In the next step shown in FIG. 12, underlying layers 32 and biaslayers 33 are deposited by sputtering obliquely to the substrate 46.

[0220] In order to perform sputtering obliquely, the substrate 46 isinclined relative to the target, or the target is inclined relative tothe substrate 46. As shown in FIG. 12, the sputtering direction ispreferably the directions T and U with an inclination θ1 relative to thevertical direction of the substrate 46, the inclination θ1 beingpreferably 20 to 50°.

[0221] By the oblique sputtering, the bias layers 33 are appropriatelydeposited on both end surfaces of the free magnetic layer 30 in thetrack width direction (the X direction) which are shaded by the resistlayer 45 when the multilayer film 21 is viewed from above.

[0222] As described above, at least portions of both end surfaces of thefree magnetic layer 30 are exposed in the step in which the insulatinglayers 31 are deposited on both end surfaces of the multilayer film 21,and thus the bias layers 33 can be formed in contact with the exposedportions of both end surfaces of the free magnetic layer 30. Therefore,a bias magnetic field can be appropriately supplied to the free magneticlayer 30 from the bias layers 33.

[0223] In this step, the formation position of the bias layers 33,particularly, the multilayer film-side end positions thereof, can bechanged by appropriately controlling the sputtering directions T and Uin deposition of the underlying layers 32 and the bias layers 33.

[0224] In the step shown in FIG. 12, the sputtering directions T and Uand the sputtering time are appropriately controlled so that themultilayer film-side ends of the upper surfaces of the bias layers 33coincide with both ends of the upper surface of the multilayer film 21.

[0225] The underlying layers 32 and the bias layers 33 formed in thisstep do not extend to the upper surface of the multilayer film 21, asshown in FIG. 12.

[0226] In depositing the underlying layers 32 and the bias layers 33 bysputtering, an underlying material film 32 a and a bias material layer33 b comprising the same materials as the underlying layers 32 and thebias layers 33, respectively, on the insulating material layer 31 b onthe resist layer 45.

[0227] Next, the resist layer 45 is separated from the multilayer film21. Since the resist layer 45 has the notched portions 45 a formed onthe lower side thereof, the resist layer 45 can easily be removed bypermeating a separating solution from the notched portions 45 a.

[0228] As shown in FIG. 13, an electrode layer 34 is formed on themultilayer film 21 and the bias layers 33.

[0229] In the step shown in FIG. 12, by changing the sputteringdirections T and U, and the sputtering time, the underlying layers 32and the bias layers 33 can be deposited by sputtering inside the notchesportions 45 a formed in the resist layer 45. This step is shown in FIG.14.

[0230] As shown in FIG. 14, the sputtering directions V and W for thesubstrate 46 have an inclination θ2 relative to the vertical directionof the substrate 46, the inclination θ2 being in the range of 30 to 60°.The inclination θ2 is slightly larger than the inclination θ1 insputtering in the step shown in FIG. 12 in which the multilayerfilm-side ends of the upper surface of the bias layer 33 coincide withboth ends 21 b of the upper surface of the multilayer film 21. Thisenables the sputtering deposition of the underlying layers 32 and thebias layers 33 inside of the notched portions 45 a of the resist layer45.

[0231] As shown in FIG. 14, the underlying layers 32 and the bias layers33 are formed to extend to the upper surface of the multilayer film 21.However, as described above with respect to the step shown in FIG. 9,the resist layer 45 is formed on the multilayer film 21 so that thewidth dimension of the lower side 45 b of the resist layer 45 coincideswith at least the width dimension of the top of the sensitive zone ofthe multilayer film, and thus the underlying layers 32 and the biaslayers 33 extended to the upper surface of the multilayer film 21 areformed only on the dead zones of the multilayer film 21, not formed onthe sensitive zone thereof. The ratio of the width dimension T2 of theextension of each of the bias layers 33 on the multilayer film 21 to thewidth dimension of the upper surface of the multilayer film 21 ispreferably 0%<(width dimension T2/width dimension of the upper surfaceof the multilayer 21)≧10%. Specifically, the width dimension T2 ispreferably 0 nm<T2≧30 nm.

[0232] FIGS. 15 to 19 are drawings showing the steps of another exampleof the method of manufacturing a tunneling magnetoresistive element ofthe present invention.

[0233] As shown in FIG. 15, an electrode layer 20 is formed on asubstrate 46, and a multilayer film 35 is formed on the electrode layer20 by sputtering. The multilayer film 35 comprises a free magnetic layer30, an insulating barrier layer 27, a pinned magnetic layer 26 and anantiferromagnetic layer 22, which are laminated in turn from the bottom.The free magnetic layer 30 comprises two layers 28 and 29, and thepinned magnetic layer 26 comprises three layers including ferromagneticlayers 23 and 25, and a nonmagnetic layer 24 and is put into aferrimagnetic state. An underlying layer of Ta or the like may be formedbelow the free magnetic layer 30, and a protecting layer of Ta or thelike is preferably formed on the antiferromagnetic layer 22.

[0234] The sensitive zone of the multilayer film 35 has previously beenmeasured by the micro-track profile method.

[0235] As shown in FIG. 15, a resist layer 45 having notched portions 45a formed on the lower side thereof is formed on the multilayer film 35.In this step, the width dimension of the lower surface 45 b of theresist layer 45 in the track width direction is set a value which is thesame as or longer than the width dimension of the sensitive zone of themultilayer film 35 in the track width direction so that the sensitivezone is completely covered with the lower surface 45 b of the resistlayer 45.

[0236] In the next step shown in FIG. 16, both side portions of themultilayer film 35 are removed by dry etching by ion milling to leave atleast the portion of the multilayer film 35, which is covered with theresist layer 45, exposing the electrode layers in the removed portions.The upper surface of the electrode layer 20 is also slightly removed byetching.

[0237] The dimension of the upper surface of the multilayer film 35 leftafter etching is longer than the width dimension of the lower surface 45b of the resist layer 45, and thus the upper surface of the multilayerfilm 35 extends from the lower surface 45 b in the track widthdirection. By this etching, both end surfaces 35 a of the multilayerfilm 35 are inclined so that the width dimension in the track widthdirection gradually increases toward the free magnetic layer 30.

[0238] In the step shown in FIG. 17, underlying layers 32 composed of Cror the like are deposited on the portions of electrode layer 20 exposedon both sides of the multilayer film 35 by sputtering in the sputteringdirections R and S which are vertical or approximately vertical to thesubstrate 46. Furthermore, bias layers 33 are deposited on theunderlying layers 32 by sputtering.

[0239] In the step shown in FIG. 17, it is necessary to takeconsideration reverse to the step shown in FIG. 11. Namely, in the stepshown in FIG. 17, the maximum width dimension T4 of the resist layer 45in the track width direction may be set to a value which is the same asor slightly longer or shorter than the width dimension of the uppersurface (i.e., the upper surface of the layer 28 shown in FIG. 17) ofthe free magnetic layer 30 in the track width direction. Therefore, atleast portions of both end surfaces of the free magnetic layer 30 areseen when the multilayer film 35 is viewed from above.

[0240] In depositing the bias layers 33 on both side surfaces of themultilayer film 35 by sputtering, the bias layers 33 are formed incontact with at least portions of both side surfaces of the freemagnetic layer 30, whereby a bias magnetic field can be appropriatelysupplied to the side surfaces of the free magnetic layer 30 from thebias layers 30 in the track width direction.

[0241] As shown in FIG. 17, an underlying material layer 32 a and a biasmaterial layer 33 b are deposited on the resist layer 45.

[0242] After the bias layers 33 are deposited, nonmagnetic intermediatelayers 36 are deposited on the bias layers 33.

[0243] In the next step shown in FIG. 18, insulating layers 31 aredeposited by sputtering on the bias layers 33 with the nonmagneticintermediate layers 36 provided therebetween so as to be located on bothsides of the multilayer film 35 in the track width direction (the Xdirection shown in the drawing). The insulating layers 31 are depositedby sputtering obliquely to the substrate 46.

[0244] The sputtering directions T and U have an inclination θ1 relativeto the vertical direction of the substrate 46, the inclination θ1 beingin the range of 20 to 500.

[0245] In the step shown in FIG. 18, by appropriately controlling thesputtering directions T and U, the sputtering time, etc., the multilayerfilm-side ends 31 a of the upper surfaces of the insulating layers 31formed on the bias layers 33 can be cause to coincide with the both ends35 b of the upper surface of the multilayer film 35. Namely, in thisstep, the insulating layers 31 are formed so as not to extend to theupper surface of the multilayer film 35. Also, a nonmagneticintermediate material layer 36 a and a insulating material layer 31 bare deposited on the resist layer 45.

[0246] The resist layer 45 shown in FIG. 18 is separated by permeating aseparating solution from the notched portions 45 a.

[0247] In the step shown in FIG. 19, an electrode layer 34 is formed onthe multilayer film 35 and the insulating layers 31.

[0248]FIG. 20 shows the step substituted for the step shown in FIG. 18.In the step shown in FIG. 20, the insulating layers 31 are formed insidethe notched portions 45 b of the resist layer 45 so as to extend to theupper surface of the multilayer film 35.

[0249] In forming the insulating layers 31 in this step, the sputteringdirections V and W have an inclination θ2 relative to the verticaldirection of the substrate, the inclination θ2 being in the range of 30to 60°. The inclination θ2 is slightly larger than the inclination θ1 insputtering in the step shown in FIG. 18 in which the multilayerfilm-side ends 31 a of the upper surfaces of the insulating layers 31coincide with both ends 35 b of the upper surface of the multilayer film35. This enables the sputtering deposition of the insulating layers 31inside of the notched portions 45 a of the resist layer 45.

[0250] In the step shown in FIG. 20, the insulating layers 31 formed toextend to the upper surface of the multilayer film 35 are formed on thedead zones of the multilayer film 35 outside the sensitive zone thereofwhich is covered with the lower surface 45 b of the resist layer 45. Theratio of the width dimension T2 of the extension of each of theinsulating layers 31 on the multilayer film 35 to the width dimension ofthe upper surface of the multilayer film 35 is preferably 0%<(widthdimension T2/width dimension of the upper surface of the multilayer35)≦10%. Specifically, the width dimension T2 is preferably 0 nm<T2≦30nm.

[0251] Each of the tunneling magnetoresistive elements shown in FIGS. 5to 8 can be manufactured by any of the above-described methods.

[0252] As shown in FIGS. 5 or 7, in depositing the ferromagnetic layers41 and the second antiferromagnetic layers 42 instead of the bias layers33, the ferromagnetic layers 41 and the second antiferromagnetic layers42 may be deposited by sputtering in the step of depositing the biaslayers 33 (FIGS. 12, 14 and 17).

[0253] As shown in FIGS. 6 or 8, in depositing the antiferromagneticinsulating layers 43 and the ferromagnetic layers 44 on both sides ofthe multilayer film, the antiferromagnetic layers 43 may be depositedinstead of the insulating layers 31 in the step shown in FIGS. 11, 19 or20, and the ferromagnetic layers 44 may be deposited instead of the biaslayers 33 in the step shown in FIGS. 12, 14 or 17.

[0254] The above-described manufacturing method of the present inventioncan easily form a tunneling magnetoresistive element with highreproducibility, as compared with a conventional method.

[0255] Namely, in the present invention, bias layers and insulatinglayers can be deposited on both sides of a multilayer film by using alift-off resist layer. Therefore, unlike a conventional manufacturingmethod (refer to FIG. 24), the present invention does not requirealignment precision and can thus form an element with highreproducibility. Although a conventional method requires an etching stepfor forming the bias layers and thus has fear of cutting a free magneticlayer in the etching step, the present invention does not require theetching step for forming the bias layers and the insulating layers,thereby protecting the free magnetic layer and causing no fear ofdeterioration in characteristics. In the present invention, by changingthe angle formed by a target and a substrate in a sputtering apparatus,the bias layers and the insulating layers can be formed in predeterminedshapes at predetermined positions on both sides of the multilayer film.Even when the bias layers or the insulating layers are formed to extendto the upper surface of the mutlilayer film, these layers are formedonly on the dead zones of the multilayer film, thereby causing no needto consider the degree of extension of the bias layers or the insulatinglayers. Therefore, the manufacturing method can be simplified andshortened.

[0256] As described above, in the present invention, the bias layers areformed on both sides of the multilayer film so as to contact portions ofboth end surfaces of the free magnetic layer, and the insulating layersare also formed on both sides of the multilayer film. The bias layers orthe insulating layers are formed so as not to extend to the uppersurface of the multilayer film.

[0257] In the above-described construction, a sensing current from anelectrode layer appropriately flows through the multilayer film, and abias magnetic field can be supplied to the free magnetic layer from thebias layers through both end surfaces. Furthermore, since the biaslayers or the insulating layers are formed so as not to extend to theupper surface of the multilayer film, the magnetic domain structure ofthe free magnetic layer can be stabilized to permit an attempt todecrease instability of the reproduced waveform and Barkhausen noise.Also, the thickness of the reproducing gap within the width dimension ofthe multilayer film in the track width direction can be made uniform.

[0258] Furthermore, in the present invention, the bias layers or theinsulating layers may be formed to extend on the dead zones of themultilayer film. Namely, the bias layers or the insulating layers areformed so as not to extend on the sensitive zone which can exhibit themagnetoresistive effect, thereby causing no fear of deterioration incharacteristics.

[0259] The method of manufacturing a tunneling magnetoresistive elementof the present invention can easily form a magnetic element with highreproducibility.

What is claimed is:
 1. A tunneling magnetoresistive element comprising amultilayer film comprising an antiferromagnetic layer, a pinned magneticlayer formed in contact with the antiferromagnetic layer so that themagnetization direction is pinned by an exchange coupling magnetic fieldwith the antiferromagnetic layer, and a free magnetic layer formed onthe pined magnetic layer with an insulating barrier layer providedtherebetween, electrode layers formed above and below the multilayerfilm, insulating layers formed on both sides of the multilayer film inthe track width direction, and domain control layers respectively formedon the insulating layers so as to contact at least portions of both endsurfaces of the free magnetic layer, for orienting the magnetizationdirection of the free magnetic layer in a direction crossing themagnetization direction of the pinned magnetic layer; wherein the domaincontrol layers are formed so as not to extend to the upper surface ofthe multilayer film.
 2. A tunneling magnetoresistive element accordingto claim 1, wherein an under laying layer is formed below each of thedomain control layers, for controlling crystal orientation of the domaincontrol layers.
 3. A tunneling magnetoresistive element according toclaim 1, wherein each of the domain control layers comprises a hardmagnetic material.
 4. A tunneling magnetoresistive element according toclaim 1, wherein each of the domain control layers comprises a laminatedfilm of a ferromagnetic layer and a second antiferromagnetic layer, theferromagnetic layers being in contact with at least portions of bothside surfaces of the free magnetic layer.
 5. A tunnelingmagnetoresistive element according to claim 1, wherein each of theinsulating layers comprises an antiferromagnetic insulating layerexhibiting an antiferromagnetic property, and each of the domain controllayers comprises a ferromagnetic layer.
 6. A tunneling magnetoresistiveelement according to claim 4, wherein the second antiferromagnetic layeris made of α-Fe₂O₃.
 7. A tunneling magnetoresistive element according toclaim 5, wherein the antiferromagnetic insulating layer is made ofα-Fe₂O₃.
 8. A tunneling magnetoresistive element comprising a multilayerfilm comprising an antiferromagnetic layer, a pinned magnetic layerformed in contact with the antiferromagnetic layer so that themagnetization direction is pinned by an exchange coupling magnetic fieldwith the antiferromagnetic layer, a free magnetic layer formed on thepined magnetic layer with an insulating barrier layer providedtherebetween, electrode layers formed above and below the multilayerfilm, insulating layers formed on both sides of the multilayer film inthe track width direction, and domain control layers formed on theinsulating layers so as to contact portions of both side surfaces of atleast the free magnetic layer, for orienting the magnetization directionof the free magnetic layer in a direction crossing the magnetizationdirection of the pinned magnetic layer; wherein the multilayer filmcomprises a central sensitive zone having excellent reproducingsensitivity so that a magnetoresistive effect can be substantiallyexhibited, and dead zones formed on both sides of the sensitive zone andhaving low reproducing sensitivity so that the magnetoresistive effectcannot be substantially exhibited; and the domain control layers areformed so as to extend on the dead zones of the multilayer film.
 9. Atunneling magnetoresistive element according to claim 8, wherein anunder laying layer is formed below each of the domain control layers,for controlling crystal orientation of the domain control layers.
 10. Atunneling magnetoresistive element according to claim 8, wherein each ofthe domain control layers comprises a hard magnetic material.
 11. Atunneling magnetoresistive element according to claim 8, wherein each ofthe domain control layers comprises a laminated film of a ferromagneticlayer and a second antiferromagnetic layer, the ferromagnetic layersbeing in contact with at least portions of both side surfaces of thefree magnetic layer.
 12. A tunneling magnetoresistive element accordingto claim 8, wherein each of the insulating layers comprises anantiferromagnetic insulating layer exhibiting an antiferromagneticproperty, and each of the domain control layers comprises aferromagnetic layer.
 13. A tunneling magnetoresistive element accordingto claim 11, wherein the second antiferromagnetic layer is made ofα-Fe₂O₃.
 14. A tunneling magnetoresistive element according to claim 12,wherein the antiferromagnetic insulating layer is made of α-Fe₂o₃.
 15. Atunneling magnetoresistive element comprising a multilayer filmcomprising a free magnetic layer, a pinned magnetic layer formed on thefree magnetic layer with an insulating barrier layer providedtherebetween, and an antiferromagnetic layer formed on the pinnedmagnetic layer, for pinning the magnetization direction of the pinnedmagnetic layer by an exchange coupling magnetic field, electrode layersformed above and below the multilayer film, domain control layers formedon both sides of the multilayer film in the track width direction so asto contact at least portions of both side surfaces of the free magneticlayer, for orienting the magnetization direction of the free magneticlayer in a direction crossing the magnetization direction of the pinnedmagnetic layer, and insulating layers formed on the domain controllayers; wherein the insulating layers are formed so as not to extend tothe upper surface of the multilayer film.
 16. A tunnelingmagnetoresistive element according to claim 15, wherein an under layinglayer is formed below each of the domain control layers, for controllingcrystal orientation of the domain control layers.
 17. A tunnelingmagnetoresistive element according to claim 15, wherein each of thedomain control layers comprises a hard magnetic material.
 18. Atunneling magnetoresistive element according to claim 15, wherein eachof the domain control layers comprises a laminated film of aferromagnetic layer and a second antiferromagnetic layer, theferromagnetic layers being in contact with at least portions of bothside surfaces of the free magnetic layer.
 19. A tunnelingmagnetoresistive element according to claim 15, wherein each of theinsulating layers comprises an antiferromagnetic insulating layerexhibiting an antiferromagnetic property, and each of the domain controllayers comprises a ferromagnetic layer.
 20. A tunneling magnetoresistiveelement according to claim 18, wherein the second antiferromagneticlayer is made of α-Fe₂O₃.
 21. A tunneling magnetoresistive elementaccording to claim 19, wherein the antiferromagnetic insulating layer ismade of α-Fe₂O₃.
 22. A tunneling magnetoresistive element comprising amultilayer film comprising a free magnetic layer, a pinned magneticlayer formed on the free magnetic layer with an insulating barrier layerprovided therebetween, and an antiferromagnetic layer formed on thepinned magnetic layer, for pinning the magnetization direction of thepinned magnetic layer by an exchange coupling magnetic field, electrodelayers formed above and below the multilayer film, domain control layersformed on both sides of the multilayer film in the track width directionso as to contact portions of both side surfaces of at least the freemagnetic layer, for orienting the magnetization direction of the freemagnetic layer in a direction crossing the magnetization direction ofthe pinned magnetic layer, and insulating layers formed on the domaincontrol layers; wherein the multilayer film comprises a centralsensitive zone having excellent reproducing sensitivity so that amagnetoresistive effect can be substantially exhibited, and dead zonesformed on both sides of the sensitive zone and having poor reproductionsensitivity so that the magnetoresistive effect cannot be substantiallyexhibited; and the insulating layers are formed so as to extend on thedead zones of the multilayer film.
 23. A tunneling magnetoresistiveelement according to claim 22, wherein an under laying layer is formedbelow each of the domain control layers, for controlling crystalorientation of the domain control layers.
 24. A tunnelingmagnetoresistive element according to claim 22, wherein each of thedomain control layers comprise a hard magnetic material.
 25. A tunnelingmagnetoresistive element according to claim 22, wherein each of thedomain control layers comprises a laminated film of a ferromagneticlayer and a second antiferromagnetic layer, the ferromagnetic layersbeing in contact with at least portions of both side surfaces of thefree magnetic layer.
 26. A tunneling magnetoresistive element accordingto claim 22, wherein each of the insulating layers comprises anantiferromagnetic insulating layer exhibiting an antiferromagneticproperty, and each of the domain control layers comprises aferromagnetic layer.
 27. A tunneling magnetoresistive element accordingto claim 25, wherein the second antiferromagnetic layer is made ofα-Fe₂O₃.
 28. A tunneling magnetoresistive element according to claim 16,wherein the antiferromagnetic insulating layer is made of α-Fe₂O₃.
 29. Amethod of manufacturing a tunneling magnetoresistive element comprising:(a) the step of forming an electrode layer on a substrate, and thenlaminating an antiferromagnetic layer, a pinned magnetic layer in whichmagnetization is pinned in a predetermined direction by an exchangecoupling magnetic field with the antiferromagnetic layer, an insulatingbarrier layer, and a free magnetic layer in turn from the bottom to forma multilayer film; (b) the step of forming, on the multilayer film, alift-off resist layer having a notched portion formed on the lower sidethereof; (c) the step of removing both sides of the mulitlayer filmleaving at least a portion of the multilayer film below the resistlayer; (d) the step of forming insulating layers on both sides of themultilayer film so that the multilayer film-side ends of the uppersurfaces of the insulating layers are lower than both ends of the uppersurface of the free magnetic layer; (e) the step of forming domaincontrol layers on the insulating layers by sputtering obliquely to thesubstrate so that the domain control layers contact both ends of thefree magnetic layer, and the multilayer film-side ends of the domaincontrol layers coincide with the both ends of the top of the multilayerfilm; and (f) the step of removing the resist layer, and forming anelectrode layer on the multilayer film and the domain control layers.30. A method of manufacturing a tunneling magnetoresistive elementaccording to claim 29, wherein an under laying layer is formed beloweach of the domain control layers, for controlling crystal orientationof the domain control layers.
 31. A method of manufacturing a tunnelingmagnetoresistive element according to claim 29, wherein in the step (d),the insulating layers or the domain control layers are formed bysputtering vertically to the substrate.
 32. A method of manufacturing atunneling magnetoresistive element according to claim 29, wherein eachof the domain control layers comprises a hard magnetic material.
 33. Amethod of manufacturing a tunneling magnetoresistive element accordingto claim 29, wherein each of the domain control layers comprises alaminated film of a ferromagnetic layer and a second antiferromagneticlayer, the ferromagnetic layers being in contact with at least portionsof both side surfaces of the free magnetic layer.
 34. A method ofmanufacturing a tunneling magnetoresistive element according to claim29, wherein each of the insulating layers comprises an antiferromagneticinsulating layer exhibiting an antiferromagnetic property, and each ofthe domain control layers comprises a ferromagnetic layer.
 35. A methodof manufacturing a tunneling magnetoresistive element according to claim29, wherein the second antiferromagnetic layer is made of α-Fe₂O₃.
 36. Amethod of manufacturing a tunneling magnetoresistive element accordingto claim 33, wherein the antiferromagnetic insulating layer exhibitingantiferromagnetism is made of α-Fe₂O₃.
 37. A method of manufacturing atunneling magnetoresistive element comprising: (g) the step of formingan electrode layer on a substrate, and then laminating anantiferromagnetic layer, a pinned magnetic layer in which magnetizationis pinned in a predetermined direction by an exchange coupling magneticfield with the antiferromagnetic layer, an insulating barrier layer anda free magnetic layer in turn from the bottom to form a multilayer film;(h) the step of forming, on a sensitive zone of the multilayer film, alift-off resist layer having a notched portion formed on the lower sidethereof; (i) the step of removing both sides of the multilayer filmleaving at least a portion of the multilayer film below the resistlayer; (j) the step of forming insulating layers on both sides of themultilayer film so that the multilayer film-side ends of the uppersurfaces of the insulating layers are lower than both ends of the uppersurface of the free magnetic layer; (k) the step of forming domaincontrol layers on the insulating layers by sputtering obliquely to thesubstrate so that the domain control layers contact both ends of thefree magnetic layer, and extend on dead zones of the multilayer film;and (l) the step of removing the resist layer, and forming an electrodelayer on the multilayer film and the domain control layers.
 38. A methodof manufacturing a tunneling magnetoresistive element according to claim37, wherein an under laying layer is formed below each of the domaincontrol layers, for controlling crystal orientation of the domaincontrol layers.
 39. A method of manufacturing a tunnelingmagnetoresistive element according to claim 37, wherein in the step (j),the insulating layers or the domain control layers are formed bysputtering vertically to the substrate.
 40. A method of manufacturing atunneling magnetoresistive element according to claim 37, wherein eachof the domain control layers comprises a hard magnetic material.
 41. Amethod of manufacturing a tunneling magnetoresistive element accordingto claim 37, wherein each of the domain control layers comprises alaminated film of a ferromagnetic layer and a second antiferromagneticlayer, the ferromagnetic layers being in contact with at least portionsof both side surfaces of the free magnetic layer.
 42. A method ofmanufacturing a tunneling magnetoresistive element according to claim37, wherein each of the insulating layers comprises an antiferromagneticinsulating layer exhibiting an antiferromagnetic property, and each ofthe domain control layers comprises a ferromagnetic layer.
 43. A methodof manufacturing a tunneling magnetoresistive element according to claim41, wherein the second antiferromagnetic layer is made of α-Fe₂O₃.
 44. Amethod of manufacturing a tunneling magnetoresistive element accordingto claim 42, wherein the antiferromagnetic insulating layer exhibitingantiferromagnetism is made of α-Fe₂O₃.
 45. A method of manufacturing atunneling magnetoresistive element comprising: (m) the step of formingan electrode layer on a substrate, and then laminating a free magneticlayer, an insulating barrier layer, a pinned magnetic layer, and anantiferromagnetic layer for pinning magnetization of the pinned magneticlayer in a predetermined direction by an exchange coupling magneticfield in turn from the bottom to form a multilayer film; (n) the step offorming, on the multilayer film, a lift-off resist layer having anotched portion formed on the lower side thereof; (o) the step ofremoving both sides of the multilayer film leaving a portion of themultilayer film below the resist layer; (p) the step of forming domaincontrol layers on both sides of the multilayer film so that themultilayer film-side ends contact at least portions of both ends of thefree magnetic layer; (q) the step of forming insulating layers on thedomain control layers by sputtering obliquely to the multilayer film sothat the multilayer film-side ends of the upper surfaces of theinsulating layers coincide with both ends of the upper surface of themultilayer film; and (r) the step of removing the resist layer, andforming an electrode layer on the multilayer film and the insulatinglayers.
 46. A method of manufacturing a tunneling magnetoresistiveelement according to claim 45, wherein an under laying layer is formedbelow each of the domain control layers, for controlling crystalorientation of the domain control layers.
 47. A method of manufacturinga tunneling magnetoresistive element according to claim 45, wherein inthe step (p), the insulating layers or the domain control layers areformed by sputtering vertically to the substrate.
 48. A method ofmanufacturing a tunneling magnetoresistive element according to claim45, wherein each of the domain control layers comprises a hard magneticmaterial.
 49. A method of manufacturing a tunneling magnetoresistiveelement according to claim 45, wherein each of the domain control layerscomprises a laminated film of a ferromagnetic layer and a secondantiferromagnetic layer, the ferromagnetic layers being in contact withat least portions of both side surfaces of the free magnetic layer. 50.A method of manufacturing a tunneling magnetoresistive element accordingto claim 45, wherein each of the insulating layers comprises anantiferromagnetic insulating layer exhibiting an antiferromagneticproperty, and each of the domain control layers comprises aferromagnetic layer.
 51. A method of manufacturing a tunnelingmagnetoresistive element according to claim 49, wherein the secondantiferromagnetic layer is made of α-Fe₂O₃.
 52. A method ofmanufacturing a tunneling magnetoresistive element according to claim50, wherein the antiferromagnetic insulating layer exhibitingantiferromagnetism is made of α-Fe₂O₃.
 53. A method of manufacturing atunneling magnetoresistive element comprising: (s) the step of formingan electrode layer on a substrate, and then laminating a free magneticlayer, an insulating barrier layer, a pinned magnetic layer, and anantiferromagnetic layer for pinning magnetization of the pinned magneticlayer in a predetermined direction by an exchange coupling magneticfield in turn from the bottom to form a multilayer film; (t) the step offorming, on a sensitive zone of the multilayer film, a lift-off resistlayer having a notched portion formed on the lower side thereof; (u) thestep of removing both sides of the multilayer film leaving at least aportion of the multilayer film below the resist layer; (v) the step offorming domain control layers on both sides of the multilayer film sothat the multilayer film-side ends contact at least portions of bothends of the free magnetic layer; (w) the step of forming insulatinglayers on the domain control layers by sputtering obliquely to themultilayer film so that the insulating layers extend on dead zones ofthe multilayer film; and (x) the step of removing the resist layer, andforming an electrode layer on the multilayer film and the insulatinglayers.
 54. A method of manufacturing a tunneling magnetoresistiveelement according to claim 53, wherein an under laying layer is formedbelow each of the domain control layers, for controlling crystalorientation of the domain control layers.
 55. A method of manufacturinga tunneling magnetoresistive element according to claim 53, wherein inthe step (v), the insulating layers or the domain control layers areformed by sputtering vertically to the substrate.
 56. A method ofmanufacturing a tunneling magnetoresistive element according to claim53, wherein each of the domain control layers comprises a hard magneticmaterial.
 57. A method of manufacturing a tunneling magnetoresistiveelement according to claim 53, wherein each of the domain control layerscomprises a laminated film of a ferromagnetic layer and a secondantiferromagnetic layer, the ferromagnetic layers being in contact withat least portions of both side surfaces of the free magnetic layer. 58.A method of manufacturing a tunneling magnetoresistive element accordingto claim 53, wherein each of the insulating layers comprises anantiferromagnetic insulating layer exhibiting an antiferromagneticproperty, and each of the domain control layers comprises aferromagnetic layer.
 59. A method of manufacturing a tunnelingmagnetoresistive element according to claim 57, wherein the secondantiferromagnetic layer is made of α-Fe₂O₃.
 60. A method ofmanufacturing a tunneling magnetoresistive element according to claim58, wherein the antiferromagnetic insulating layer exhibitingantiferromagnetism is made of α-Fe₂O ₃.